Compounds of general formula (I): wherein                R1 may denote C1-C8-alkyl,                    heteroaryl which is unsubstituted or mono- or polysubstituted with a branched or unbranched C1-C4-alkyl group, a cycloalkyl group, a branched or unbranched C1-C4-alkoxy group, an NH2-group or a primary or secondary amino group, a trifluoromethyl group, a cyano or nitro group or halogen,            aryl which is unsubstituted or mono- or polysubstituted with a branched or unbranched C1-C4-alkyl group, a branched or unbranched C1-C4-alkoxy group, a NH2-group or a primary or secondary amino group of a trifluoromethyl group, a hydroxy, cyano or nitro group or halogen or with a 5- or 6-membered heteroaryl group which may contain one, two, three, four or five heteroatoms selected from among nitrogen, oxygen or sulphur, which may be identical or different,            alkylaryl which is unsubstituted or mono- or polysubstituted in the aryl and/or alkyl partial structure with a branched or unbranched C1-C4-alkyl group, a branched or unbranched C1-C4-alkoxy group, an NH2-group or a primary or secondary amino group of a trifluoromethyl group of a cyano or nitro group or halogen,optionally in the form of the individual tautomers or possibly enantiomers and the mixtures thereof as well as in the form of the free bases or the corresponding acid addition salts with pharmacologically acceptable acids,are known from published German Application DE 198 43 489. This publication also describes, in particular, the compound 4-(4-(2-pyrrolylcarbonyl)-1-piperazinyl)-3-trifluoromethyl-benzoylguanidine methanesulphonate, namely                         
Because of their activity as inhibitors of the cellular Na+/H+ exchange, compounds of this kind may be used as active substances in pharmaceutical compositions or as intermediate products for preparing such active substances. The compounds according to the invention are effective against arrhythmias such as those which occur in cases of hypoxia, for example. They may also be used to treat diseases related to ischaemia (such as cardiac, cerebral, gastrointestinal diseases—such as mesenteric thrombosis/embolism, pulmonary, renal ischaemia, ischaemia of the liver, ischaemia of the skeletal musculature). Such diseases may be, for example, coronary heart disease, myocardial infarction, angina pectoris, stable angina pectoris, ventricular arrhythmias, subventricular arrhythmias, cardiac insufficiency—and also to assist bypass operations, to assist open heart surgery, to assist operations which require interruption of the blood supply to the heart and to assist heart transplants—embolism in the pulmonary circulation, acute or chronic kidney failure, chronic kidney insufficiency, cerebral infarction, reperfusion injury caused by the restoration of circulation to areas of the brain after the removal of vascular occlusions and acute and chronic circulatory disorders of the brain. The abovementioned compounds may also be used in conjunction with thrombolytic agents such as t-PA, streptokinase and urokinase.
When the ischaemic heart is reperfused (e.g. after an attack of angina pectoris or a myocardial infarction) there may be irreversible damage to cardiomyocytes in the affected region. The compounds according to the invention have a cardioprotective effect, inter alia, in such a case.
The field of ischaemia should also include the prevention of damage to transplants (e.g. as a protection for the transplanted organ—such as for example a liver, kidney, heart or lung—before, during and after implantation as well as during storage of the transplants), which may occur in connection with transplants. The compounds are, moreover, drugs with a protective effect during angioplastic surgical procedures on the heart and on peripheral blood vessels.
In essential hypertension and diabetic nephropathy the cellular sodium proton exchange is increased. The compounds according to the invention are therefore suitable as inhibitors of this exchange for the preventive treatment of these diseases.
The compounds according to the invention are further characterised by a strongly inhibiting effect on the proliferation of cells. Therefore, the compounds are useful as drugs for treating illnesses in which cell proliferation plays a primary or secondary role and may be used as agents against cancers, benign tumours, or for example prostatic hypertrophy, atherosclerosis, organ hypertrophies and hyperplasias, fibrotic diseases and late complications of diabetes.
Moreover, compounds of this type are known to be capable of favourably influencing the blood levels of the serum lipoproteins.
When they are administered parenterally some local intolerances occasionally arise. 4-(4-(2-Pyrrolylcarbonyl)-1-piperazinyl)-3-trifluoromethyl-benzoylguanidine hydrochloride was found to have a haemolytic activity and to be locally poorly tolerated after intravenous administration.
The poor tolerance often has completely different causes. On the one hand it could be the physical/chemical properties of the preparation such as its pH value, buffer capacity, tonicity, which deviate to a greater or lesser extent from the physiological conditions at the injection or infusion site and lead to unwanted reactions there, particularly when administered over lengthy periods. On the other hand the active substance itself may interact undesirably with the morphological structures at the injection or infusion site.
The following procedures for improving tolerance are known from Way, S. and Brazeau, G.: “Techniques to Reduce Pain and Irritation”, Interpharm Press 1999, p. 215 ff, p. 247 ff:                a) diluting the medication with a conventional carrier, equivalent to administering it over a longer period        b) administering it through large blood vessels, i.e. a central vein instead of a peripheral vein        c) giving a local anaesthetic or analgesic beforehand or simultaneously.        
The principle of these procedures is to reduce the actual concentration of the formulation or of the active substance.
The disadvantages of these measures, depending on the indication, are that                a) as a result of the dilution an undesirably large volume is administered, resulting in an undesirably high fluid loading of the patient;        b) the period of administration is extended;        c) administration through a central vein requires experience and technical equipment which is not always available in emergencies;        d) the use of a local anaesthetic might possibly be contraindicated.        
The objective of the present invention is to formulate the sodium-proton exchange inhibitor 4-(4-(2-pyrrolylcarbonyl)-1-piperazinyl)-3-trifluoromethyl-benzoylguanidine or one of the pharmacologically acceptable acid addition salts thereof in such a way that, immediately during and after intravenous administration, there is no local intolerance of the kind observed when aqueous, isotonic solutions were administered to animals without any measures being taken to improve tolerance. The improvement in tolerance should not be achieved by any of the conventional methods such as increasing the volume administered or extending the infusion period. The improvement in local tolerance is of crucial importance for emergency injections of a bolus.